Many water providers monitor adenosine triphosphate (ATP) as an indicator of biological acclimation of their biofilters; however, strong correlations between ATP concentration and filter performance (e.g., organic matter or disinfection by-product precursor removal) are not typically observed. As an alternative, this study evaluated the use of enzyme activity for monitoring biological processes within filters. Recent studies have proposed that enzyme activity may be used as an indicator of biofilter function as it provides a means to quantify biodegradation which may allow for a more accurate measure of degradation potential and to gain a better understanding of biofilter performance. Sampling was completed from full- and pilot-scale biofilters to assess impacts associated with pre-treatments, varying sources waters, as well as pre-treatment and operating conditions. Enzyme activity (carboxylic esterase, phosphatase, ß-glucosidase, α-glucosidase, ß-xylosidase, chitinase, and cellulase) and ATP were measured from the top 5 cm of biofilter media representative of typical full-scale sampling; water quality parameters included dissolved organic carbon (DOC) and disinfection by-products (DBPs): trihalomethane (THM) formation potential (FP), and haloacetic acid FP (HAA FP). Results confirmed that ATP was not a reliable monitoring tool for DOC and DBP FP reduction in biofilters. A strong relationship was observed between esterase activity and DOC reduction; chitinase activity significantly correlated to THM FP reduction for filters treating three different source waters and HAA FP reduction achieved by filters treating the same source water with a range of pre-treatment and backwash conditions. This study showed that enzyme activity may be appropriate for monitoring biological processes within drinking water filters and may act as a surrogate for the removal of organic compounds.

许多供水商将三磷酸腺苷 (ATP) 作为其生物过滤器生物适应的指标进行监测；然而，通常不会观察到 ATP 浓度与过滤器性能（例如，有机物或消毒副产物前体去除）之间的强相关性。作为替代方案，本研究评估了酶活性在过滤器内监测生物过程的用途。最近的研究提出，酶活性可以用作生物过滤器功能的指标，因为它提供了一种量化生物降解的方法，可以更准确地测量降解潜力并更好地了解生物过滤器的性能。采样是从全规模和中试规模的生物过滤器完成的，以评估与预处理、不同源水、以及预处理和操作条件。酶活性（羧酸酯酶、磷酸酶、β-葡萄糖苷酶、α-葡萄糖苷酶、β-木糖苷酶、几丁质酶和纤维素酶）和 ATP 从代表典型全尺寸采样的生物过滤介质的顶部 5 厘米处测量；水质参数包括溶解有机碳 (DOC) 和消毒副产物 (DBP)：三卤甲烷 (THM) 形成潜力 (FP) 和卤乙酸 FP (HAA FP)。结果证实，ATP 不是生物过滤器中 DOC 和 DBP FP 减少的可靠监测工具。在酯酶活性和 DOC 减少之间观察到很强的关系；几丁质酶活性与处理三种不同源水的过滤器的 THM FP 减少和通过使用一系列预处理和反冲洗条件处理相同源水的过滤器实现的 HAA FP 减少显着相关。该研究表明，酶活性可能适用于监测饮用水过滤器内的生物过程，并可作为去除有机化合物的替代物。